Aerochargers are better than a twin screw!! hahaha ;-)

[Stephen Webb]

> loss in the motor due to the higher backpressure on it, you are STILL
> getting more total useful work (flywheel HP plus compressor HP) out of a
> given amount of  fuel burned (or amount of air breathed) because of the
> higher overall expansion ratio which exists in the motor/turbo system.

Ahh, I see. 

To some extent it seems like we would care less about how much work is
extracted from the turbine, though.  Since the work you extract from the
turbine is not being used to drive the car, but to add more air to the
engine, you can't be justified in counting it, can you?  I could agree
that it has a higher thermal efficiency, but it seems like, in
the end, we care about how much power you can take off of the crank, and
how much fuel you had to burn to do so. 

For instance, a highly efficient turbine hooked to a crappy
compressor.  The turbine extracts gobs of power from the exhaust, but uses
it to drive a low efficiency compressor, which in the end produces the
same crank horsepower.(as a high efficiency compressor would)  Higher
termal efficiency, but unchanged or lower fuel efficiency...?

It seems like a lot of energy is wasted when the wastegate opens.  Any
thoughts on driving an electrical generator instead of a compressor -
control turbine speed by load, never wasting energy through the
wastegate...Use the electricity for an electric drive motor to boost the
cars acceleration...

Spins too fast?  Too expensive?  hmm...

-Steve


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